Opening a file for editing - file

Question

I want to create a method that will load a txt file and then change it but thats another method.
private void openFile() {
fileChooser.getSelectedFile();
JFileChooser openFile = new JFileChooser();
openFile.showOpenDialog(frame);
}
What must go next in order to get data from the file after choosing it to manipulate its data?

Answer 1

The JFileChooser documentation has an example on how to continue your code, and get the name of the file chosen, which can then be turned into a File object. You should be able to modify that example to meet your needs:
JFileChooser chooser = new JFileChooser();
FileNameExtensionFilter filter = new FileNameExtensionFilter(
"JPG & GIF Images", "jpg", "gif");
chooser.setFileFilter(filter);
int returnVal = chooser.showOpenDialog(parent);
if(returnVal == JFileChooser.APPROVE_OPTION) {
System.out.println("You chose to open this file: " +
chooser.getSelectedFile().getName());
}

Answer 2

Here's an example that might help you. I would want to read up on and try some simple examples on different buffers that will read and write. In fact, i have worked with these a lot in the last few months and I still have to go and look.
public class ReadWriteTextFile {
static public String getContents(File aFile) {
StringBuilder contents = new StringBuilder();
try {
BufferedReader input = new BufferedReader(new FileReader(aFile));
try {
String line = null; //not declared within while loop
while (( line = input.readLine()) != null){
contents.append(line);
contents.append(System.getProperty("line.separator"));
}
}
finally {
input.close();
}
}
catch (IOException ex){
ex.printStackTrace();
}
return contents.toString();
}
static public void setContents(File aFile,
String aContents)
throws FileNotFoundException,
IOException {
if (aFile == null) {
throw new IllegalArgumentException("File should not be null.");
}
if (!aFile.exists()) {
throw new FileNotFoundException ("File does not exist: " + aFile);
}
if (!aFile.isFile()) {
throw new IllegalArgumentException("Should not be a directory: " + aFile);
}
if (!aFile.canWrite()) {
throw new IllegalArgumentException("File cannot be written: " + aFile);
}
Writer output = new BufferedWriter(new FileWriter(aFile));
try {
output.write( aContents );
}
finally {
output.close();
}
}
public static void main (String... aArguments) throws IOException {
File testFile = new File("C:\\Temp\\test.txt");//this file might have to exist (I am not
//certain but you can trap the error with a
//TRY-CATCH Block.
System.out.println("Original file contents: " + getContents(testFile));
setContents(testFile, "The content of this file has been overwritten...");
System.out.println("New file contents: " + getContents(testFile));
}
}